C5AR1 and COVID-19: In addition to CR1 antagonist, blocking of CR3 can inhibit NET formation in response to certain pathogens.192,193 A recent study has indicated that in neutrophils infected with SARS-CoV-2, the process of NETosis might be amplified by C5a/C5aR1 signaling, while treatment of neutrophils with DF2593A, a selective C5aR1 allosteric antagonist, inhibits NET formation, which provides a promising therapeutic strategy for COVID-19.194